Create azure arm nodes without providing network interface

## Feature Request
I'm having difficulty creating nodes with the azure arm driver. As I can understand, it requires providing an existing network interface, and to create a network interface, an existing subnet, IP, and virtual network are needed. I don't find methods to create them. The way to create azure nodes is not intuitive as other providers.

I wonder if it's possible to make the create_node method in the azure arm driver without providing a network interface? Or if there is an example of creating nodes for the azure arm driver?

Start with the Azure ARM driver's create_node method and trace how it currently handles the required network interface. Determine whether the intended outcome is automatic network-resource creation or an example showing the existing workflow; completion should be defined before implementation because the request leaves those alternatives open.

索引モデルが issue の本文から書いたものです。